Solenoid actuated electrical device



April 3, 1962 A. vAccARo 3,028,587

SOLENOID ACTUATED ELECTRICAL DEVICE Filed Dec. 14, 1959 INVENTOR. jf zye a I dccarO M {LO/m9 iinite r 3,ii28,587 Patented Ap 1962 3,028,587 SQLENOID ACTUATED ELECTRICAL DEVICE Angelo Vaccaro, 28 Dunwood Road, Port Washington, NY. Filed Dec. 14, 1959, Ser. No. 85%481 1 Claim. (Cl. 340-252) The present invention relates to electric devices of the type having a solenoid energized by electric current to actuate a movable armature, such as a relay and more particularly to such a device which when energized provides for a low voltage power source which may be employed to actuate a signal device to indicate that the solenoid is energized.

An electrical device having a solenoid and a movable armature is a relay of the magnetic type which has the coil or solenoid encircling a portion of an armature and which when the coil is energized, the armature is moved to close switches. The present invention is hereinafter set forth as applied to a relay in order to describe one specific embodiment of the invention though the invention is not to be considered as limited solely to relays, as it may be employed with other devices which have a coil that, when energized, magnetically causes an armature to move.

When relays or other solenoid actuated devices are employed in remote or unexposed locations to control energization of a load, it has been found desirable to provide some indication that may be easily observed of the state of the solenoid, i.e. whether or not it is energized. Normally such an indication consists of a pilot light that normally operates on a voltage which is much lower than the solenoid operating voltage or the load voltage controlled by the relay. To provide energy for operation of the light, there has heretofore been proposed many systems, such as a step-down transformer, a drop resistor or other voltage decreasing devices. Such systems, how ever, have not been completely satisfactory in view of the factors of expense, maintenance requirements and leads carrying high voltage when only a low voltage is necessary. 7

It is an object of the present invention to provide a solenoid actuated device in which the device upon energization provides a low voltage power source from the power employed to energize the solenoid and such power source may provide the energy for a circuit that indicates when the solenoid is energized.

Another object of the present invention is to provide in a solenoid operated device of the above type for the obtaining of the low voltage power directly from the solenoid by induction.

A further object of the present invention is to provide a solenoid operated device in which the above objects are achieved in a simple and durable structure and that may be economically incorporated in conventional solenoids with little alterations in their structure.

In carrying out the above objects, the device of the present invention includes a solenoid comprising a coil of wire wound to encompass a portion of a magnetic armature and in view of the invention being described as applied to a relay there are switch means that are actuated by the magnetism induced in the armature when the coil is energized by alternating current. To provide the low voltage power source for energizing an indicating circuit only when the coil is energized, a length of wire is associated with the coil in a manner which enables a low voltage to be induced in the coil whenever the coil is energized. This may be accomplished, according to one form of the present invention, by providing a secondary winding wrapped around the coil while in another form of the present invention, the coil is tapped. Thus the former embodiments function as a transformer to provide the low voltage power while the latter acts as an autotransformer in producing the low voltage power.

Other features and advantages will hereinafter appear.

In the drawings:

FIGURE 1 is a schematic diagram of a relay having the present invention incorporated therein connected in a circuit to provide an indication when the relay is energized.

FIG. 2'is a schematic view of a portion of a coil or solenoid and the armature.

FIG. 3 is a schematic diagram similar to FIG. 1 of a further embodiment of the present invention.

FIG. 4 is a view similar to FIG. 2 of the further embodiment of the present invention.

Referring to the drawing, FIG. 1, a relay is generally indicated by the reference numeral 10 and has a solenoid or coil 11 inductively associated with a switch arm 18 as by the coil encircling a portion of the armature in a manner well-known in the art. The ends of the coil 11 are connected to a source of alternating current 13 as by lines 14 and 15. A normally closed stop switch 16 and a normally open start switch 17 are positioned in the line 15 to control the energization of the coil 11. While the relay of the present invention may be of the normally closed type, it is specifically illustrated as being of the normally opened type having switch means including a movable switch arm 18 and contacts 19 and 20. The switch arm 18 is connected to a lead 21 while a lead 22 connects to the contact 2i) such that the switch means controls energization of a load 23 by a source of power 24. The structure of the switch arm and core 29 may be of any desired construction as may the switches operated by the switch arm, it being appreciated that the present invention may be employed in any solenoid actuated electrical device.

In accordance with the present invention wherein a low voltage power source is obtained by induction from the energization of the coil 11, there is provided a secondary winding 25 wound to be in inductive relationship with the coil and switch arm of the relay and the ends of the winding are connected to an indicating means, such as a pilot light 26. It will be appreciated that normally the sources of power 13 and 24 are at least v. while pilot lights usually operate at 6 v. and hence cannot be connected directly to either of the power sources. Moreover, the leads connecting the pilot light 26 to the winding 25 only have a small voltage such as 6 v. thereacross, rather than the higher voltages of the power sources 13 and 24, thereby enabling a more economical wire to be employed with greater safety and versatility.

Shown in FIG. 2 is a sectional View of a portion of the relay coil and the armature. The coil includes a flanged cylindrical form 2.7 with the coil 11 wound thereon from a length of wire 28. A core 29 of magnetic material extends through the coil. An armature 18 is pivoted as at 31 on the form 27. Movement of the armature 18 may serve to actuate a switch in any desired manner. In this embodiment of the invention, the low voltage power source coil 25 is a separate and distinct coil with respect to the coil or solenoid 11 and hence consists of a length of wire 32 wound about the exterior of the turns of the coil 11 to have a voltage induced therein upon A.C. energization of the coil 11. Thus, in effect, the two coils 11 and 25 act like a transformer having a primary and secondary winding.

In FIG. 3, rather than having a separate winding for producing the low voltage power for the indicating circuit, a coil 33 is tapped intermediate its ends as at 34 and connected by leads 35 and 36 to a pilot light 37. The other parts of the circuit are identical to that shown in FIG. 1 and hence have been given the same reference numeral.

As shown in FIG. 4, the low voltage power source may be efficiently derived simply by tapping the solenoid or coil 33 in any well-known manner, one simple and effective way being that shown of a tap 4t soldered directly to the wire of the coil. With this construction, there is provided a low voltage for the indicating circuit by the solenoid 33 functioning as an autotransformer having a tap.

It will be understood that the value of the voltage of the low voltage power source may be set by the number of turns in the winding 25 or the number of turns of the coil 33 between the tap and the end of the coil, and hence is capable of being set at any desired value with respect to the coil operating voltage.

it will accordingly be appreciated that the solenoid actuated device of the present invention provides for a source of low voltage from the solenoid which may be employed to power low voltage indicating structures, such as a pilot light. The voltage is derived from the solenoid either by a separate winding wound to function as the secondary of a transformer with a solenoid being the primary or it may consist of a portion of the solenoid with this portion acting as an autotransformer. In both embodiments of the invention the low power source operates only when the solenoid is energized and in addition may be simply and eifectively incorporated into existing solenoids with a minimum of alteration in the solenoid.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

An electrical relay including a switch for closing and opening a load circuit; a magnetizable core; a coil of electrical conducting wire wound to encircle a substantial portion of the core and in permanent inductive relation therewith; an armature in magnetic relation with said core for operating said switch when said coil is energized; a supply circuit for supplying alternating current to said coil, said circuit including a manually-operable normally open starting switch and a manually-operable normally closed stopping switch to control the operation of said first-named switch; and signal means for producing a steady signal to indicate when the coil is energized comprising a signal lamp, :1 low voltage circuit for energizing said signal lamp and a signal coil of electrical conducting wire having a relatively small number of turns wound about the exterior of said first-named coil and in inductive relation with the latter and said core whereby an EMF. is induced in said signal coil having a voltage determined by the number of its turns about said firstnamed coil, said signal means being electrically insulated from said supply circuit and said load circuit, except for said inductive relation.

References Qited in the tile of this patent UNITED STATES PATENTS 2,465,059 Campbell Mar. 22, 1949 2,528,898 Mcllvaine Nov. 7, 1950 FOREIGN PATENTS 700,247 Great Britain Nov. 25, 1953 

